Hi, I was watching Japanese anime sort of about WWIII, and there one of the private Japanese militaries (basically, an UN para-military organization that HQ in Japan) was fighting side by side with what they called the " Great North American Empire (or US, they had all US attributes)." So, the intersting part are the depiction of the insignias. Note,that most of the insignias are guesses, but if they were all, they would be look like something akin to this:

They are suppousadly a metalic stampt rectangles with metalic pin in it, they are collar rank insignias, for BDU, for both soldiers, NCO's, and officers. Unfortunatly, the anime only depicted fighting chronicals, so there no full dress of any kind.

Something called Platinumhugen Ordian a 24 episoder about some wars (mostlytwo wars, one in Asia, Vietnam war with mechs, the other in Japan/Germany, basicallly a rebellion) and giant (for most part small sizes, though) mechs. More information here, at this link:
http://www.animenewsnetwork.com/encyclo ... hp?id=3124